code: def step(self, *, noise_multiplier: float, sample_rate: float):
      if len(self.history) >= 1:
          (
              last_noise_multiplier,
              last_sample_rate,
              num_steps,
          ) = self.history.pop()
          if (
              last_noise_multiplier == noise_multiplier
              and last_sample_rate == sample_rate
          ):
              self.history.append(
                  (
                      last_noise_multiplier,
                      last_sample_rate,
                      num_steps + 1,
                  )
              )
          else:
              self.history.append(
                  (last_noise_multiplier, last_sample_rate, num_steps)
              )
              self.history.append((noise_multiplier, sample_rate, 1))
  
      else:
          self.history.append((noise_multiplier, sample_rate, 1))
  
file_path: opacus/opacus/accountants/rdp.py
imports: from typing import List, Optional, Tuple, Union
  from .accountant import IAccountant
  from .analysis import rdp
label_desc: Use image node_id 2 for calling the RDPAccountant obj's underlying member method code with example usage: obj.step() without return types